1. Field of the Invention
This invention is concerned with the production of internal isomers from linear phenylalkane mixtures via selective cracking of the 2-phenylalkane in the presence of a shape-selective zeolite catalyst.
2. Description of the Invention
Detergent alkylates comprising linear phenylalkylsulfonates are known to be useful and desirable detergents. Phenyldodecylsulfonate in particular is widely employed in the detergent industry and it is known that the location on the alkyl chain of the average phenyl group has significant effect on the detergency properties of the sulfonate. For instance, it has been demonstrated that by shifting the average phenyl group location to more internal positions one increases the solubility, wetting power and foaming power of the phenyldodecylsulfonates. Tjepkena et al., 5th World Petroleum Congress, Sect. 4, No. 21 (1959).
Phenyldodecylsulfonate is prepared from phenyldodecane intermediate, the position of the phenyl group in the intermediate being fixed during the initial reaction of benzene with the linear olefin. The production of the intermediate is conventionally carried out in the presence of a Friedel-Crafts catalyst (e.g. AlCl.sub.3) to give a mixture of all of the possible positional isomers. Many attempts to reduce the external phenyl isomer concentration (i.e. the 2-phenylalkane), and thereby increase the relative amount of the more desirable internal isomers (the 3-phenyl, the 4-phenyl, etc.), have been reported, but only small reductions of the 2-phenyl isomer content have been achieved.